In net bags known at present for packing fruit and the like, it is conventional to use welding or stapling effected transversely to the tube of continuous net from which the bags are formed in succession. The net tube is fed continuously into the packing machine and the process of closing the bag consists in effecting a first transverse welding or stapling of the tubular element, then filling the bag with the predetermined weight of pieces of fruit and subsequently effecting a further welding or stapling operation in the upper portion, which delimits the bag, and at the same time producing a further upper transverse weld, corresponding to the bottom of the following bag and finally cutting the tubular net element in the region between the two adjacent upper welds or staples.
That process is economical and enables bags that are closed by welding or stapling at both ends to be obtained. However, when the bags are put to practical use by the consumers who purchase them, it is often convenient to use only some of the pieces of fruit contained in the bag. This is difficult because, in the currently known bags, once the closure produced by welding has been destroyed, the bag cannot be closed again and therefore all of its contents have to be removed and placed elsewhere.